Detergent motor fuel containing substituted ureas

ABSTRACT

A class of substituted ureas represented by the formula: IN WHICH X HAS A VALUE FROM TWO TO FOUR, R is hydrogen or a hydrocarbyl radical and R&#39;&#39; and R&#39;&#39;&#39;&#39; are hydrocarbyl radicals having from eight to 20 carbon atoms have been found to be useful as carburetor detergents in a motor fuel composition.

III I e Inventor Ronald W. Von AlImen Hopewell Junction, NIT. Appl. No.23,027 Filed Mar. 26, 1970 Patented Oct. 26, 1971 Assignee Texaco Inc.

New York, NY.

DETERGENT MOTOR FUEL CONTAINING [56] References Cited UNITED STATESPATENTS 2,839,372 6/1958 Lindstrom et a] 44/66 3,468,639 9/1969Lindstrom et al 44/66 Primary Examiner-Daniel E. Wyman AssistantExaminer-W. J. Shine Attorneys-Thomas H. Whaley and Carl G. RiesABSTRACT: A class of substituted ureas represented by the formula:

I I I I R--N(CHz)x-NCNICHDr-NR in which x has a value from two to four,R is hydrogen or a hydrocarbyl radical and R and R" are hydrocarbylradicals having from eight to 20 carbon atoms have been found to beuseful as carburetor detergents in a motor fuel composition.

DETERGENT MOTOR FIUEIL CONTAINING SUESTITUTHED UREAS BACKGROUND OF THEINVENTION Field of the Invention deposits in and around the throttleplate area of the carburetor. These deposits restrict the flow of airthrough the carburetor at idle and at low speeds so that an overrichfuelmixture results. This condition produces rough engine idling,stalling and also results in excessive hydrocarbon exhaust emissions tothe atmosphere.

DESCRIPTION OF THE PRIOR ART Numerous patents have issued disclosing theuse of urea derivatives to effect improvements in gasoline compositions.

US. Pat. No. 2,373,372 discloses alkylated and arylated ureas forimproving the antiknock value of gasoline. U.S. Pat. No. 2,683,08ldiscloses N-hydrocarbyLN'-hydroxyphenyl ureas as anti-oxidants forgasoline. U.S. Pat. No. 2,772,148 disclosesN-alkyl-N',N-di(carboxymethyl) urea as a rust inhibitor for hydrocarbonfuels.

SUMMARY OF THE INVENTION A class of relatively high molecular weightsubstituted ureas are provided as carburetor detergents when employed ina liquid hydrocarbonaceous fuel for an internal combustion engine. Theseureas are characterized by having a pair of long chain alkylamino alkylradicals substituted on the basic urea structure and appear to be uniquein their detergency properties.

The fuel composition of the invention mitigates or overcomes the problemof deposits laydown in the carburetor of an internal combustion engine.When a gasoline of the invention is employed in a carburetor which has asubstantial buildup of deposits from prior operations, a severe test ofthe detergency property of the fuel, this gasoline is very effective forremoving substantial amounts of these preformed deposits.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The substituted urea additiveemployed in this invention has the formula:

H O H in which x has the value of from two to four, R is hydrogen or ahydrocarbyl radical having from one to four carbon atoms, and R and R"respectively are hydrocarbyl radicals having from eight to 20 carbonatoms each.

In a preferred embodiment R is hydrogen .1: has a value of 3,

and R and R" each represent a saturated secondary aliphatic radicalhaving from [0 to 15 carbon atoms.

The additive of the invention can be prepared by reacting urea with asuitable dihydrocarbon-substituted amine or diamine to produce the notedcompound. A preferred reaction is to react urea with anNalkyl-substituted trimethylenediamine. In this procedure, two moles ofthe diamine are reacted with a mole of urea at an elevated temperatureto produce the desired product. The molar proportion of the reaction,the reaction product can be dissolved in a suitable solvent, such asether-benzene, washed with dilute acidic and basic solutions until theproduct is slightly basic, dried, and recovered from the solvent byvacuum distillation. This reaction is described in Synthesis ofSymmetrical Ureas by Heating Urea With a Primary Amine" by J. G.Erickson, .I. Am. Chem. 500., 76, 3977 I954).

Examples of compounds that are effective carburetor detergents ingasoline include 3,3-di(dodecylamino) di-n-propylurea,3,3'-di(tetradecylamino) di-n-propylurea, 3,3'-di(octadecylamino)di-n-propylurea, 3-dodecylamino-3'-octadecylamino di-n-propylurea,2,2'-di(dodecylamino) di-nethylurea, 4,4'-di(hexadecylamino)di-n-butylurea, 3,3- di(sec. C ,H alkylamine) di-n-propylurea and 3,3-di(octadecenylamine) di-n-propylurea.

Any gasoline suitable for a spark-ignited, internal combustion enginecan be used in the practice of this invention. In general, the base fuelwill consist of a mixture of hydrocarbons in the gasoline boiling range,i.e. from about 75 to 450 F.

The hydrocarbon components can consist of paraffinic,

naphthenic, aromatic and olefinic hydrocarbons obtained by thermal orcatalytic cracking or reforming of petroleum hydrocarbons. This basefuel will generally have a Research Octane Number above and preferablyabove 90.

The substituted urea of the invention can be advantageously employed inthe motor fuel at a concentration ranging from about 0.0005 to 0.05weight percent. The preferred concentration ofthe additive is from about0.001 to 0.0l weight percent.

The following examples illustrate the preparation of the substitutedureas of the invention.

EXAMPLEI 180 g. (0.60 mole) of N-cocoprop ylenediamine (commercialDuomeen C) was placed in a 500 ml. flask equipped with a thermometer,condenser, magnetic stirrer and a sintered glass tube. 18 g. (0.30 mole)of urea was added and themixture heated for 3 hours at I60" C. A slowsteady nitrogen flow was maintained to sweep out ammonia being evolved.The nitrogen flow was continued until the reaction product returned toroom temperatures. The reaction product was diluted with approximately600 ml. of ether-benzene and washed alternately with 6Xl00 ml. of 1.5 Nhydrochloric acid. After washing with 6Xl00 ml. of 10 percent sodiumcarbonate, the product was washed with water until the wash was slightlybasic, i.e. less than pH 8. The product was dried over CaSO, and Na sOfiltered and the solvent removed by vacuum distillation at 0.5 mm. Hg.ove-ra steam bath.

The N-cocopropylenediamine-urea derivative, also known as3,3'di(cocoamino) di-n-propylurea, had a total Base Number (ASTM D-664)of 167 (Theory 178) and a nitrogen content of 9.3 percent (Theory 8.9).Duomeen C is an Armour Company product having the formula R-NH-(Cll h-NH, where R is an alkyl radical derived from coconut fatty acids.

EXAMPLE II 0.60 moles of N-oleyl propylenediamine (commercial Duomeen 0)and 0.30 moles of urea were reacted as in example I. The substitutedurea derivative, 3l,3'di(oleylamino) di-npropylurea, had a total basenumber of (Theory and a nitrogen content of 7.04 percent (Theory 7.02).Duomeen 0 is similar in structure to Duomeen C except that the alkylradical represented by R in the formula above is octadecenyl.

EXAMPLE II] 0.60 moles of N-(B-undecyU-l,3-propanediamine (commercialDuomeen L-l 1) and 0.30 moles of urea were reacted as in example Iabove. The substituted urea derivative had a total base number of I78(Theory 194) and a nitrogen content of9.9 percent (Theory 9.7

EXAMPLE IV 0.60 moles of N-(B-pentadecyD-l,3-propanediamine (commercialDuomeen L-l) and 0.30 moles of urea were reacted as in example I. Thesubstituted urea derivative had a total base number of 140 (Theory 162)and a nitrogen content of 8.3 percent (Theory 8.1).

EXAMPLE V 0.60 moles of N-sec.(C -C alkyl-1,3-propanediamine and 0.30moles of urea were reacted as in example I. The substituted urea had atotal base number of 205 (Theory 204) and a nitrogen content of 10.7(Theory 10.2).

EXAMPLE VI hydrocarbons, 20 percent olefinic hydrocarbons and 55 percentparaffmic hydrocarbons and boiled in the range from about 90 F. to 360F.

The carburetor detergency test results obtained from the base fuelcontaining the substituted ureas described above are set forth in thefollowing table. The additive-containing fuels contained the activedetergent additive at a concentration of 5 ptb (pounds per thousandbarrels of fuel), a concentration equal to about 0.002 weight percent. Aminor amount of a light distillate mineral oil carrier introduced in thefuel with the additive has no significant effect on the test results.

The foregoing tests, Runs 2, 4, 6, 8 and 10, show that the substitutedurea additive of the invention provides a very substantial improvementin the detergent properties of gasoline as compared to the base fuel.These improvements are also in marked contrast to the results obtainedwith a gasoline containing di-N-sec. (C alkylurea and theineffectiveness of Run 12 shows that there is criticality in thestructure of the substituted urea in order to obtain effectivecarburetor detergency.

The motor fuel composition of the invention can contain any of theadditives normally used in gasoline including corrosion inhibitors,antioxidants, anti-icing TABLE I.- ClIEVROLET (/ARBUREIOR DETERGENCYTEST DEPUSIT REMOVAL Deposit Deposit Percent huildremoved, A Fuel up,mg. 1 mg. tive percent BasofueL. 16.7 6.3 38 Base plus 51TB Example 122.5 18.1 80 42 Basefuel.......... 22.2 4.5 20 Base plus 5 PTB Example11.... 23.6 15.3 65 .Basefuel 21.6 4.!) 23 Base plus 5 PTB Example 111 124. 4 20. 7 85 62 Base fuel 18. 5 3. 9 21 Base plus 5 P'IB Example IV,23.3 14.2 61 40 Base fuel 1 27.1 2 +2.8 -10 Base plus 5 PTB Example V24. 1 12.6 52 62 Base fuel 17.4 +2.5 14.4 Base plus 5 PTB Example Vl..15.5 +2.3 l3.2 1.2

1 Built up with base fuel. 1 Additional deposits formed.

a Chevrolet V-8 engine mounted on a test stand using amodified fourbarrel carburetor. The two secondary barrels of the carburetor aresealed and the feed to each of the primary barrels arranged so that anadditive fuel can be run in one barrel and a base fuel run in the other.The primary carburetor barrels were also modified so that they hadremovable aluminum inserts in the throttle plate area in order thatdeposits formed on the inserts in this area could be convenientlyweighed.

In the procedure designed to determine the effectiveness of an additivefuel to remove preformed deposits in the carburetor, the engine is runfor a period of time usually 24 or 48 hours using the base fuel as thefeed to both barrels with engine blow-by circulated to the air inlet ofthe carburetor. The weight of the deposits on both sleeves is determinedand recorded. The engine is then cycled for 24 additional hours withbase fuel being fed to one barrel, additive fuel to the other and noblow-by to the carburetor air inlet. The inserts are then removed fromthe carburetor and weighed to determine the difference between theperformance of the additive and nonadditive fuels in removing thepreformed deposits. After the aluminum inserts are cleaned, they arereplaced in the carburetor and the process repeated with the fuelsreversed in the carburetor barrels to minimize differences in fueldistribution and barrel construction. The deposit weights in the tworuns are averaged and the effectiveness of the base fuel and of theadditive fuel for removing deposits expressed in percent.

The base fuel employed in the following examples was a premium gradegasoline having a Research Octane Number of about 101 and containing 3cc. of tetraethyl lead per gallon. This gasoline consisted of about 25percent aromatic compounds and antiknock agents, such as tetraethyllead, tetramethyl lead and mixtures thereof.

lclaim:

l. A motor fuel composition comprising a mixture of hydrocarbon in thegasoline boiling range and a minor detergent amount of a substitutedurea represented by the formula:

in which x has a value from 2 to 4 R is hydrogen or a hydrocarbylradical having from one to four carbon atoms and R and R respectivelyare hydrocarbyl radicals having from eight to 20 carbon atoms. g "I w 2.A motor fuel composition according to claim 1 in which x has a value of3 and R and R are aliphatic hydrocarbon radicals.

3. A motor fuel composition according to claim 1 containing from about0.0005 to 0.05 weight percent of said substituted urea.

4. A motor fuel composition according to claim 1 m which 1: has a valueof 3 and R and R are aliphatic hydrocarbon radicals having from 10-15carbon atoms.

5. A motor fuel composition according to claim 1 in which saidsubstituted urea is 3.3 '-di(cocoamino) di-n-propylurea.

6. A motor fuel composition according to claim 1 in which saidsubstituted urea is 3,3'-di[sec.(C C, )alkylamino]-din-propylurea.

7. A motor fuel according to claim 1 in which said substituted urea is3,3-di(oleylamino)-di-n-propylurea.

2. A motor fuel composition according to claim 1 in which x has a valueof 3 and R'' and R'''' are aliphatic hydrocarbon radicals.
 3. A motorfuel composition according to claim 1 containing from about 0.0005 to0.05 weight percent of said substituted urea.
 4. A motor fuelcomposition according to claim 1 in which x has a value of 3 and R'' andR'''' are aliphatic hydrocarbon radicals having from 10-15 carbon atoms.5. A motor fuel composition according to claim 1 in which saidsubstituted urea is 3,3''-di(cocoamino) di-n-propylurea.
 6. A motor fuelcomposition according to claim 1 in which said substituted urea is3,3''-di''(sec.(c10-C15)alkylamino)-di-n-propylurea.
 7. A motor fuelaccording to claim 1 in which said substituted urea is3,3''-di(oleylamino)-di-n-propylurea.